The present invention is directed to a one-piece cable tie, and more particularly, to a one-piece cable tie having stepped down strap body teeth to improve engagement between the locking wedge and the strap body at small bundle diameters.
Cable ties are well known and generally include an elongated strap body integrally formed with a head having a strap body passageway which includes a strap body locking mechanism for securing the strap body around a bundle of wires or cables. Typically, cable tie strap body teeth have their peaks even with or slightly below the top surface of the side rails. As shown in FIG. 4, in prior art cable ties this height remains the same throughout the length of the cable tie strap body.
Due to the orientation of the locking wedge within the head and the natural tendency for the strap body to straighten, the strap body teeth push against the locking wedge when the cable tie is installed, especially when the cable tie reaches smaller bundle diameters. During rapid cable tie threading, the strap body teeth exert excessive force on the first tooth of the locking wedge. As a result, the first tooth becomes deformed and elongated. A strap body tooth adjacent the strap body tooth contacting the first tooth of the locking wedge may push the locking wedge out of engagement before the elongated wedge tooth can drop into engagement with the strap body teeth. This disengagement effect is more pronounced for smaller bundle diameters, such as one inch or less.
It would be desirable to provide a cable tie having two or more cable tie strap body teeth sections of various depths to improve locking wedge engagement on small bundle applications.
It would also be desirable to provide a cable tie having a step down in strap body teeth depth to increase the distance between the wedge ramp of the locking wedge and the strap body teeth peaks.
It would further be desirable to provide a cable tie having stepped down strap body teeth to provide additional spacing for an elongated locking wedge tooth to pivot down into engagement with the strap body teeth.
The invention includes a cable tie having stepped down strap body teeth. The cable tie comprises a strap body having a first end and a second end opposite the first end, a locking head secured to the first end of the strap body, and a plurality of walls on the locking head forming a strap body accepting channel. The strap body includes a first group of teeth having a first predetermined depth and a second group of teeth having a second predetermined depth. The depth of the first group of teeth is between 0.001 and 0.007 inches greater than the depth of the second group of teeth.
Preferably, the depth of the first group of teeth is 0.003 inches greater than the depth of the second group of teeth.
Preferably, the first group of teeth is adjacent the first end of the strap body.